Bill Gates can take a great deal of the credit for the fact that not a single
case of polio was recorded in India last year.

Last year, an astonishing milestone was passed: not a single Indian contracted polio. A disease that once ravaged both the developed and developing world has been restricted to a handful of countries, and to hundreds of cases rather than millions. Complete eradication will be difficult, but there is still a strong chance that polio could soon follow smallpox into the dustbin of history.

For this extraordinary achievement, Britain can claim some credit. This time last year, for example, David Cameron agreed to double our contribution to the eradication campaign, and he has also increased funding for other vaccination programmes: this nation now inoculates a child every two seconds (and saves a life every two minutes). The lion’s share of the praise, however, should go to the man who will be beside Andrew Mitchell, the Development Secretary, in Davos today – Bill Gates, the US billionaire. It is Mr Gates’s foundation (alongside the charity Rotary International) that has turbocharged the global effort, putting pressure on governments to support what is, by any standards, a remarkable achievement in public health.

Mr Gates brought to bear not just private sector funding, but private sector expertise and efficiency. Commendably, Mr Mitchell has reconfigured our aid strategy to draw more on these qualities. Yet there is a cultural lesson here, too. Mr Gates and his friend Warren Buffett are great philanthropists – and they have also persuaded a host of their fellow plutocrats, from Ted Turner to Michael Bloomberg to Mark Zuckerberg, to follow them in donating most of their fortune to good causes. Such philanthropy is one of America’s greatest blessings, and it is bolstered by a tax system that goes out of its way to encourage it. If Britain wants to maximise the good it does in the world, the Treasury should follow suit.